diff --git a/.chloggen/prwreceiver-content-type.yaml b/.chloggen/prwreceiver-content-type.yaml new file mode 100644 index 000000000000..a340558053c4 --- /dev/null +++ b/.chloggen/prwreceiver-content-type.yaml @@ -0,0 +1,27 @@ +# Use this changelog template to create an entry for release notes. + +# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix' +change_type: enhancement + +# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver) +component: receiver/prometheusremotewrite + +# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`). +note: Implement Content-Type negotiation for Prometheus Remote Write requests + +# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists. +issues: [35565] + +# (Optional) One or more lines of additional information to render under the primary note. +# These lines will be padded with 2 spaces and then inserted directly into the document. +# Use pipe (|) for multiline entries. +subtext: Warning - The HTTP Server still doesn't do anything. It's just a placeholder for now. + +# If your change doesn't affect end users or the exported elements of any package, +# you should instead start your pull request title with [chore] or use the "Skip Changelog" label. +# Optional: The change log or logs in which this entry should be included. +# e.g. '[user]' or '[user, api]' +# Include 'user' if the change is relevant to end users. +# Include 'api' if there is a change to a library API. +# Default: '[user]' +change_logs: [api, user] diff --git a/receiver/prometheusremotewritereceiver/receiver.go b/receiver/prometheusremotewritereceiver/receiver.go index b533cfc2dce8..3d6557249853 100644 --- a/receiver/prometheusremotewritereceiver/receiver.go +++ b/receiver/prometheusremotewritereceiver/receiver.go @@ -8,12 +8,15 @@ import ( "errors" "fmt" "net/http" + "strings" "time" + promConfig "github.com/prometheus/prometheus/config" "go.opentelemetry.io/collector/component" "go.opentelemetry.io/collector/component/componentstatus" "go.opentelemetry.io/collector/consumer" "go.opentelemetry.io/collector/receiver" + "go.uber.org/zap/zapcore" ) func newRemoteWriteReceiver(settings receiver.Settings, cfg *Config, nextConsumer consumer.Metrics) (receiver.Metrics, error) { @@ -31,8 +34,8 @@ type prometheusRemoteWriteReceiver struct { settings receiver.Settings nextConsumer consumer.Metrics - config *Config - server *http.Server + config *Config + server *http.Server } func (prw *prometheusRemoteWriteReceiver) Start(ctx context.Context, host component.Host) error { @@ -64,6 +67,53 @@ func (prw *prometheusRemoteWriteReceiver) Shutdown(ctx context.Context) error { return prw.server.Shutdown(ctx) } -func (prw *prometheusRemoteWriteReceiver) handlePRW(_ http.ResponseWriter, _ *http.Request) { - fmt.Println("handleWrite called") +func (prw *prometheusRemoteWriteReceiver) handlePRW(w http.ResponseWriter, req *http.Request) { + contentType := req.Header.Get("Content-Type") + if contentType == "" { + prw.settings.Logger.Warn("message received without Content-Type header, rejecting") + http.Error(w, "Content-Type header is required", http.StatusUnsupportedMediaType) + return + } + + msgType, err := prw.parseProto(contentType) + if err != nil { + prw.settings.Logger.Warn("Error decoding remote-write request", zapcore.Field{Key: "error", Type: zapcore.ErrorType, Interface: err}) + http.Error(w, err.Error(), http.StatusUnsupportedMediaType) + return + } + if msgType != promConfig.RemoteWriteProtoMsgV2 { + prw.settings.Logger.Warn("message received with unsupported proto version, rejecting") + http.Error(w, "Unsupported proto version", http.StatusUnsupportedMediaType) + return + } +} + +// parseProto parses the content-type header and returns the version of the remote-write protocol. +// We can't expect that senders of remote-write v1 will add the "proto=" parameter since it was not +// a requirement in v1. So, if the parameter is not found, we assume v1. +func (prw *prometheusRemoteWriteReceiver) parseProto(contentType string) (promConfig.RemoteWriteProtoMsg, error) { + contentType = strings.TrimSpace(contentType) + + parts := strings.Split(contentType, ";") + if parts[0] != "application/x-protobuf" { + return "", fmt.Errorf("expected %q as the first (media) part, got %v content-type", "application/x-protobuf", contentType) + } + + for _, part := range parts[1:] { + parameter := strings.Split(part, "=") + if len(parameter) != 2 { + return "", fmt.Errorf("as per https://www.rfc-editor.org/rfc/rfc9110#parameter expected parameters to be key-values, got %v in %v content-type", part, contentType) + } + + if strings.TrimSpace(parameter[0]) == "proto" { + ret := promConfig.RemoteWriteProtoMsg(parameter[1]) + if err := ret.Validate(); err != nil { + return "", fmt.Errorf("got %v content type; %w", contentType, err) + } + return ret, nil + } + } + + // No "proto=" parameter found, assume v1. + return promConfig.RemoteWriteProtoMsgV1, nil } diff --git a/receiver/prometheusremotewritereceiver/receiver_test.go b/receiver/prometheusremotewritereceiver/receiver_test.go new file mode 100644 index 000000000000..63e89b3c835d --- /dev/null +++ b/receiver/prometheusremotewritereceiver/receiver_test.go @@ -0,0 +1,77 @@ +// Copyright The OpenTelemetry Authors +// SPDX-License-Identifier: Apache-2.0 + +package prometheusremotewritereceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/prometheusremotewritereceiver" + +import ( + "context" + "fmt" + "net/http" + "testing" + + promConfig "github.com/prometheus/prometheus/config" + "github.com/stretchr/testify/assert" + "go.opentelemetry.io/collector/component/componenttest" + "go.opentelemetry.io/collector/consumer/consumertest" + "go.opentelemetry.io/collector/receiver/receivertest" +) + +func TestHandlePRWContentTypeNegotiation(t *testing.T) { + factory := NewFactory() + cfg := factory.CreateDefaultConfig() + + prwReceiver, err := factory.CreateMetricsReceiver(context.Background(), receivertest.NewNopSettings(), cfg, consumertest.NewNop()) + assert.NoError(t, err) + assert.NotNil(t, prwReceiver, "metrics receiver creation failed") + + ctx, cancel := context.WithCancel(context.Background()) + t.Cleanup(cancel) + + assert.NoError(t, prwReceiver.Start(ctx, componenttest.NewNopHost())) + t.Cleanup(func() { + assert.NoError(t, prwReceiver.Shutdown(ctx), "Must not error shutting down") + }) + + for _, tc := range []struct { + name string + contentType string + extectedCode int + }{ + { + name: "no content type", + contentType: "", + extectedCode: http.StatusUnsupportedMediaType, + }, + { + name: "unsupported content type", + contentType: "application/json", + extectedCode: http.StatusUnsupportedMediaType, + }, + { + name: "x-protobuf/no proto parameter", + contentType: "application/x-protobuf", + extectedCode: http.StatusUnsupportedMediaType, + }, + { + name: "x-protobuf/v1 proto parameter", + contentType: fmt.Sprintf("application/x-protobuf;proto=%s", promConfig.RemoteWriteProtoMsgV1), + extectedCode: http.StatusUnsupportedMediaType, + }, + { + name: "x-protobuf/v2 proto parameter", + contentType: fmt.Sprintf("application/x-protobuf;proto=%s", promConfig.RemoteWriteProtoMsgV2), + extectedCode: http.StatusOK, + }, + } { + t.Run(tc.name, func(t *testing.T) { + req, err := http.NewRequest(http.MethodPost, "http://localhost:9090/api/v1/write", nil) + assert.NoError(t, err) + + req.Header.Set("Content-Type", tc.contentType) + resp, err := http.DefaultClient.Do(req) + assert.NoError(t, err) + + assert.Equal(t, tc.extectedCode, resp.StatusCode) + }) + } +}